U.S. patent application number 16/531599 was filed with the patent office on 2021-02-11 for enhanced radio frequency band scanning.
The applicant listed for this patent is T-Mobile USA, Inc.. Invention is credited to Wafik Abdel Shahid, Gina Tran.
Application Number | 20210045044 16/531599 |
Document ID | / |
Family ID | 1000004233674 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210045044 |
Kind Code |
A1 |
Tran; Gina ; et al. |
February 11, 2021 |
ENHANCED RADIO FREQUENCY BAND SCANNING
Abstract
Techniques are described herein for optimizing band scanning for
one or more bands supported by a mobile device for connection to a
wireless network. The techniques include determining geolocation
coordinates corresponding to a real-time location of a mobile
device. The mobile device may identify at least one available radio
frequency (RF) band supported by the mobile device based at least
on the geolocation coordinates. In some aspects, the mobile device
may determine whether a signal quality of the available RF band is
above a predetermined threshold. If the signal quality of the
available RF band is above the predetermined threshold, the mobile
device may selectively prioritize a scan for support by a wireless
network of the available RF band and connect to the wireless
network using the available RF band.
Inventors: |
Tran; Gina; (Seattle,
WA) ; Abdel Shahid; Wafik; (Kenmore, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
T-Mobile USA, Inc. |
Bellevue |
WA |
US |
|
|
Family ID: |
1000004233674 |
Appl. No.: |
16/531599 |
Filed: |
August 5, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 24/08 20130101;
H04W 48/16 20130101 |
International
Class: |
H04W 48/16 20060101
H04W048/16; H04W 24/08 20060101 H04W024/08 |
Claims
1. One or more non-transitory computer-readable media storing
computer-executable instructions that upon execution cause one or
more processors to perform acts comprising: determining geolocation
coordinates corresponding to a real-time location of a mobile
device; identifying at least one available radio frequency (RF)
band supported by the mobile device based at least on the
geolocation coordinates; determining whether a signal quality of
the at least one available RF band is above a predetermined
threshold; prioritizing a scan for support by a wireless network of
the at least one available RF band in response to determining that
the signal quality of the at least one available RF band is above
the predetermined threshold; and connecting to the wireless network
using the at least one available RF band.
2. The one or more non-transitory computer-readable media of claim
1, wherein the acts further comprise: determining an aggregate
bandwidth of a first RF band and a second RF band of the at least
one available RF band; and selectively prioritizing scanning for
support by the wireless network of the first RF band if the
aggregate bandwidth of the first RF band is greater than the
aggregate bandwidth of the second RF band.
3. The one or more non-transitory computer-readable media of claim
2, wherein the acts further comprise: determining whether the
mobile device is connected to the wireless network using the first
RF band; and selectively prioritizing scanning for support by the
wireless network of the second RF band if the mobile device is not
connected to the wireless network using the first RF band.
4. The one or more non-transitory computer-readable media of claim
1, wherein the acts further comprise: determining whether a signal
strength of the at least one available RF band is above an
additional predetermined threshold; performing an additional scan
for support by the wireless network of the at least one available
RF band in response to determining that the signal quality of the
at least one available RF band is above the additional
predetermined threshold; and connecting to the wireless network
using the at least one available RF band.
5. The one or more non-transitory computer-readable media of claim
1, wherein the wireless network comprises a home public land mobile
network (HPLMN) or a visited public land mobile network
(VPLMN).
6. The one or more non-transitory computer-readable media of claim
5, wherein the acts further comprise: triggering the scan when the
mobile device is connected to the VPLMN.
7. The one or more non-transitory computer-readable media of claim
1, wherein the at least one available RF band comprises a last used
RF band.
8. A computer-implemented method, comprising: determining
geolocation coordinates corresponding to a real-time location of a
mobile device; identifying at least one available radio frequency
(RF) band supported by the mobile device based at least on the
geolocation coordinates; determining whether a signal quality of
the at least one available RF band is above a predetermined
threshold; prioritizing a scan for support by a wireless network of
the at least one available RF band in response to determining that
the signal quality of the at least one available RF band is above
the predetermined threshold; and connecting to the wireless network
using the at least one available RF band.
9. The computer-implemented method of claim 8, further comprising:
determining an aggregate bandwidth of a first RF band and a second
RF band of the at least one available RF band; and selectively
prioritizing scanning for support by the wireless network of the
first RF band if the aggregate bandwidth of the first RF band is
greater than the aggregate bandwidth of the second RF band.
10. The computer-implemented method of claim 9, further comprising:
determining whether the mobile device is connected to the wireless
network using the first RF band; and selectively prioritizing
scanning for support by the wireless network of the second RF band
if the mobile device is not connected to the wireless network using
the first RF band.
11. The computer-implemented method of claim 8, further comprising:
determining whether a signal strength of the at least one available
RF band is above an additional predetermined threshold; performing
an additional scan for support by the wireless network of the at
least one available RF band in response to determining that the
signal quality of the at least one available RF band is above the
additional predetermined threshold; and connecting to the wireless
network using the at least one available RF band.
12. The computer-implemented method of claim 8, wherein the
wireless network comprises a home public land mobile network
(HPLMN) or a visited public land mobile network (VPLMN).
13. The computer-implemented method of claim 8, wherein the at
least one available RF band comprises a last used RF band.
14. The computer-implemented method of claim 13, further
comprising: triggering the scan when the mobile device is not
connected to the wireless network using the last used RF band.
15. A system, comprising: one or more non-transitory storage
mediums configured to provide stored computer-readable
instructions, the one or more non-transitory storage mediums
coupled to one or more processors, the one or more processors
configured to execute the computer-readable instructions to cause
the one or more processors to: determine geolocation coordinates
corresponding to a real-time location of a mobile device; identify
at least one available radio frequency (RF) band supported by the
mobile device based at least on the geolocation coordinates;
determine whether a signal quality of the at least one available RF
band is above a predetermined threshold; prioritize a scan for
support by a wireless network of the at least one available RF band
in response to determining that the signal quality of the at least
one available RF band is above the predetermined threshold; and
connect to the wireless network using the at least one available RF
band.
16. The system of claim 15, wherein the one or more processors are
further configured to: determine an aggregate bandwidth of a first
RF band and a second RF band of the at least one available RF band;
and selectively prioritize scanning for support by the wireless
network of the first RF band if the aggregate bandwidth of the
first RF band is greater than the aggregate bandwidth of the second
RF band.
17. The system of claim 16, wherein the one or more processors are
further configured to: determine whether the mobile device is
connected to the wireless network using the first RF band; and
selectively prioritize scanning for support by the wireless network
of the second RF band if the mobile device is not connected to the
wireless network using the first RF band.
18. The system of claim 15, wherein the one or more processors are
further configured to: determine whether a signal strength of the
at least one available RF band is above an additional predetermined
threshold; perform an additional scan for support by the wireless
network of the at least one available RF band in response to
determining that the signal quality of the at least one available
RF band is above the additional predetermined threshold; and
connect to the wireless network using the at least one available RF
band.
19. The system of claim 15, wherein the wireless network comprises
a home public land mobile network (HPLMN) or a visited public land
mobile network (VPLMN).
20. The system of claim 15, triggering the scan when the mobile
device is not connected to a last acquired network cell of the
wireless network.
Description
BACKGROUND
[0001] Mobile devices can support several radio frequency (RF)
bands for various radio technologies, and wireless networks
typically support more than one RF band, which refer to a defined
range of frequencies or wavelengths in an electromagnetic spectrum.
To connect to a wireless network over a detected band, the mobile
device can utilize a list hardcoded onto the mobile device that it
then scans through when the mobile device is powered on, moved back
into a coverage area, or when toggled off from an airplane mode.
With the proliferation of radio frequencies that telecommunications
service providers own and operate on, in addition to roaming
agreements with other telecommunications service providers,
scanning through all the available bands that the mobile device
supports can take a prolonged period of time, resulting in a poor
user experience.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] The detailed description is described with reference to the
accompanying figures, in which the leftmost digit(s) of a reference
number identifies the figure in which the reference number first
appears. The use of the same reference numbers in different figures
indicates similar or identical items.
[0003] FIG. 1 illustrates example network architecture for scanning
for a preferred band of a plurality of bands supported by a mobile
device based at least on geolocation coordinates of the location of
the mobile device.
[0004] FIG. 2 is a block diagram showing various components of an
illustrative computing device that can be used for establishing
wireless communication using optimized band scanning.
[0005] FIG. 3 is a flow diagram of an example process for scanning
for a preferred band in a wireless network when a mobile device is
powered on or when toggled off from an airplane mode, in accordance
with various aspects of the present disclosure.
[0006] FIG. 4 is a flow diagram of an example process for scanning
for a preferred band in a wireless network when a mobile device is
roaming, in accordance with various aspects of the present
disclosure.
[0007] FIG. 5 is a flow diagram of an example process for selecting
a preferred band to scan from a plurality of available bands.
DETAILED DESCRIPTION
[0008] This disclosure is directed to techniques for optimizing
band scanning at a mobile device. When a mobile device is powered
on, its first task from a radio point of view is to search for a
suitable network and then attempt to register. To speed up the
task, the mobile device is guided by information on the Universal
Integrated Circuit Card (UICC) (e.g., Subscriber Identity Module
(SIM) card) stored in the home network with an access technology
field. With this field, the network operator can instruct the
mobile device for which radio access technology (e.g., Global
System for Mobile Communications (GSM), Universal Mobile
Telecommunication System (UMTS), Long-Term Evolution (LTE)) to
search first and then use for registration. To shorten the search
process, the mobile device stores the parameters of the last
network cell it used before it was switched off, whereby the
network cell can include a microcell, a femtocell, and/or a
picocell. After the device is powered on (or toggled off from an
airplane mode), it can go to the last known band and use the last
known cell parameters to see if the network cell can still be
found. This can increase the speed of the cell search procedure if
the mobile device has not been carried to another place while it
was switched off and the last used radio access technology is the
same as the network operator preference stored on the UICC.
[0009] In the case where the previous network cell is not found
with the stored information, the mobile device performs a full
search. During the first step of the LTE cell search mechanism, the
mobile device searches on all channels in all supported frequency
bands for an initial signal and tries to pick up a Primary
Synchronization Signal (PSS). Once found, the device remains on the
channel and locates the Secondary Synchronization Signal (SSS).
While the content of the PSS is always the same, the content of the
SSS is alternated in every frame so that the mobile device can
detect from the pattern as to where to find the beginning of the
frame.
[0010] To make the network cell detection easier, the network cell
may broadcast PSS and SSS only on a predetermined frequency of the
channel, such as the inner 1.25 MHz of the channel, irrespective of
the total channel bandwidth. This way, a simpler Fast Fourier
Transformation (FFT) analysis can be performed to detect the
signals. Also, the initial cell search is not dependent on the
channel bandwidth. The PSSs and SSSs implicitly contain the
Physical Cell Identity (PCI), which distinguishes neighboring
network cells transmitting on the same frequency. Mobile devices
receive several PSS and SSS and can, therefore, detect several PCIs
on the same frequency. After detection of the PSS and SSS, the
mobile device is also aware if the network cell uses a normal or an
extended cyclic prefix. The signals transmitted from the different
network cells on the same channel interfere with each other.
[0011] As a channel is used only by one operator (except at
national borders), the mobile device would attempt to start
communication only with the network cell with the strongest
synchronization signals and ignore the other network cells on the
same frequency. In the case where the mobile device has found the
network cell it used before it was switched off, it may go directly
to the last used network cell and stop searching for other network
cells on different channels in the current frequency band, even if
the network cell is not the strongest on the current channel. After
a successful attach procedure, the cell reselection mechanism or a
handover can ensure that the mobile device is served by the
strongest network cell it receives.
[0012] The next step in the cell search procedure is to read the
system information (SI) messages of the Master Information Block
(MIB) from the Physical Broadcast Channel (PBCH). The MIB contains
information about the configuration of the channel for initial
access, such as the total bandwidth used for the channel, the
structure of the Hybrid Automatic Retransmission Request (HARM)
indicator channel, and the System Frame Number (SFN). With the
information from the MIB, the mobile device can then begin to
search for the System Information Block 1 (SIB-1). Once found, the
SIB-1 message contains the cell identity and access-related
parameters, the Mobile Country Code (MCC) and Mobile Network Code
(MNC) of the network cell, the Nonaccess Stratum (NAS) cell
identifier, the Tracking Area Code (TAC), cell barring status,
minimum reception level that the mobile device must receive the
network cell with, and a scheduling list of other SIBs that are
sent and their intervals.
[0013] With the information provided in SIB-1, the mobile device
can decide if it wants to start communicating with this network
cell. If so, for example, since the network cell belongs to the
home network, the mobile device then continues to search and decode
further SI messages. SIB-2 contains further parameters that are
required to communicate with a network cell, such as the
configuration of the Random Access Channel (RACH), the paging
channel configuration, the downlink shared channel configuration,
the Physical Uplink Control Channel (PUCCH) configuration, the
Sounding References Signal (SRS) configuration in the uplink,
uplink power control information; timers and constants, and uplink
channel bandwidth. Further SIBs contain information that is mainly
relevant for cell reselection once the mobile device has
established a connection with the network. If the network cell is
not part of the home network or does not belong to the last used
network stored on the mobile device (e.g., during international
roaming), the mobile device then goes on and searches other
channels on the current frequency band and also on other RF
bands.
[0014] Example embodiments relate to techniques for a mobile device
to optimize band scanning by identifying and selectively
prioritizing at least one preferred RF band of a wireless network
to scan from a plurality of bands supported by the mobile device
when the mobile device is powered on, moves back into a coverage
area, or when toggled off from an airplane mode. For example, the
mobile device may enter the coverage area of a first RF band of a
wireless network and connect to the wireless network using the
first RF band. Subsequently, the mobile device may be powered off
and carried to a different location. Upon powering back on, the
mobile device may attempt to re-establish a connection to a last
acquired network cell of the wireless network using the first RF
band (i.e., the last used RF band). If the mobile device is unable
to establish the connection via the first RF band, the mobile
device determines the geolocation coordinates (i.e., longitude and
latitude) of its location using location services to identify one
or more available RF bands.
[0015] Upon identifying one or more available RF bands, the mobile
device determines whether the signal quality of an available RF
band exceeds a predetermined threshold. If the signal quality of
the available RF band is above the predetermined threshold, the
available RF band is preferred over other bands that the mobile
device supports. Accordingly, the mobile device may scan the
wireless network to determine if the preferred RF band is supported
before other bands are scanned. Subsequently, the mobile device may
perform multiple scans if the available RF band is not supported.
In some aspects, more than one available band may provide an
acceptable signal quality. In this case, the aggregate bandwidths
of the available bands are compared to select the band with the
most bandwidth. Multiple scans may be performed, depending upon
embodiments. The techniques described herein may be implemented in
a number of ways. Example implementations are provided below with
reference to the following figures.
Example Network Architecture
[0016] FIG. 1 illustrates example architecture for scanning for a
preferred band of a plurality of bands supported by a mobile device
based at least on geolocation coordinates of the location of the
mobile device and signal quality. The architecture may include a
mobile device 110 in a wireless communication network 100. The
mobile device 110 can include smartphones, personal digital
assistants (PDAs), handheld devices, tablet computers, laptops,
display devices (e.g., TVs, computer monitors), printers, general
computers, or other user equipment having a wireless communication
function that is capable of receiving input, processing the input,
and generating output data. While only one mobile device 110 is
illustrated, the architecture may include multiple mobile
devices.
[0017] The mobile device 110 can communicate with an access network
(e.g., a radio access network (RAN), an access point (AP), etc.)
over a physical communications interface or network access
technologies. For example, the air interface 108 may serve the
mobile device 110 over a local wireless connection. The air
interface 108 can comply with a given cellular communications
protocol. For example, the network can implement 2G, 3G, 4G, 5G,
LTE, LTE advanced, high-speed data packet access (HSDPA), evolved
high-speed packet access (HSPA+), UMTS, code-division multiple
access (CDMA), GSM, a local area network (LAN), a wide area network
(WAN), and/or a collection of networks (e.g., the Internet). The
air interface 108 can also comply with a wireless IP protocol
(e.g., Wi-Fi, IEEE 802.11).
[0018] The RAN 106 can include a plurality of APs 112(1)-112(N)
that serve the mobile device 110 over air interface 108. The Aps
112(1)-112(N) can serve a respective coverage cell (e.g.,
microcell, femtocell, picocell, etc.). In one aspect, an AP in the
RAN 106 can be referred to as an access node (AN), a base station,
Node B, evolved Node B (eNode B), and/or so forth. An AP can
alternatively be a terrestrial access point or a satellite access
point. The RAN 106 connects to a core network 104 that can perform
a variety of functions, including bridging circuit switched calls
between mobile devices served by the RAN 106 and other mobile
devices served by the RAN 106 or a different RAN. The RAN 106 can
also mediate an exchange of packet-switched (PS) data with external
networks such as the Internet 102. The Internet 102 can include a
number of routing agents and processing agents (not shown).
[0019] The core network 104 can provide one or more communications
services (e.g., voice-over-Internet Protocol (VoIP) sessions,
push-to-talk (PTT) sessions, group communication sessions, etc.)
for mobile device 110. The mobile device 110 can connect to the
core network 104 via the RAN 106 and/or the Internet 102. Other
mechanisms of connecting to the core network 104 are also possible
for the mobile device 110, such as over wired access networks,
Wi-Fi networks (e.g., based on IEEE 802.11, etc.) and so on.
[0020] In the illustrated embodiment, the mobile device 110 may
communicate with the APs 112(1)-112(N), which may be separate from
the RAN 106. The APs 112(1)-112(N) can be connected to the Internet
102 independent of the core network 104. Each AP can have a
geographic coverage area such that the mobile device 110 can
communicate with an AP based on its location. For instance, the
first AP 112(1) covers the first geographic area 118 and the second
AP 112(N) covers the second geographic area 120. The coverage areas
can differ in size and may overlap at least partially. The mobile
device 110 can be covered by more than one AP (e.g., at a
transition point or a coverage boundary) and can, therefore,
associate with the APs 112(1)-112(N) at different times. The first
AP 112(1) may support a first RF band 114 and the second AP 112(N)
may support a second RF band 116. In various embodiments, one AP
may support multiple bands.
[0021] The mobile device 110 may be a multi-band device that is
configured to support a plurality of bands. For example, the mobile
device 110 may be a quad-band GSM phone that uses GSM service in
the 850-MHz, 900-MHz, 1800-MHz, or 1900-MHz band. Accordingly, the
mobile device 110 may include an RF band connection framework for
monitoring or controlling logic, circuits, etc., to perform scans
for an RF band and establishing a connection with a wireless
network. In various embodiments, the RF band connection framework
determines the order in which bands are scanned by selectively
prioritizing which bands to scan first when attempting to connect
to the network 100. Thus, the order in which bands are scanned as
determined by the RF band connection framework is generally
different from the order in which bands are scanned by the default
setting of the mobile device 110.
[0022] In the illustrated embodiment, the mobile device 110 may
connect to the first AP 112(1) while in the first geographic area
118. Accordingly, the mobile device 110 may support the first RF
band 114. Subsequently, the mobile device 110 may be triggered to
scan for second RF band 116 when the mobile device 110 is moved to
the second geographic area 120 from the first geographic area 118.
For example, the mobile device 110 may be moved to the second
geographic area 120 while the mobile device 110 is powered off.
Similarly, the mobile device 110 may enter an airplane mode in the
first geographic area 118 and be moved to the second geographic
area, where the mobile device 110 is toggled off from the airplane
mode.
[0023] When the mobile device 110 is powered on or toggled off from
the airplane mode, the RF band connection framework of the mobile
device 110 may attempt to reconnect to the network 100 using the
first RF band 114 (i.e., the last used RF band). Upon determining
that the first RF band 114 is not available or upon determining
that the mobile device cannot connect to the first AP 112(1) using
the first RF band 114, the RF band connection framework may trigger
band scanning. For instance, the RF band connection framework
receives the mobile device's geolocation coordinates (i.e.,
latitude and longitude) from the mobile device's 110 location
services, such as a Global Positioning System (GPS) or an assisted
GPS (A-GPS) service of the mobile device 110. The location services
may monitor the real-time or near real-time location information of
the mobile device 110. The RF band connection framework uses the
geolocation coordinates to determine whether latitude and/or
longitude of the geolocation coordinates are within a range of
available bands supported by the mobile device 110 to connect to
the network 100.
[0024] The RF band connection framework can identify one or more
available bands based on location information or geolocation
coordinates of the location of the mobile device 110 received from
location services of the mobile device 110. The RF band connection
framework can then compare the available bands to identify a band
with acceptable signal quality. The available band with acceptable
signal quality is identified as a preferred band and scanned first
during the scanning process. If there are multiple available bands
with acceptable signal quality, the RF band connection framework
compares aggregate bandwidth to select a band with the most
bandwidth. The available band with acceptable signal quality having
the most bandwidth is more preferred over another available band
having less bandwidth and therefore scanned first because a band
with higher bandwidth can support more transmission modes. If the
band with the most bandwidth is not supported by the wireless
network, the band with the second most bandwidth is scanned second,
and so on until the mobile device 110 selects a network cell to
connect to the wireless network.
[0025] In another example, the scans may be triggered while the
signal strength of the first RF band 114 is greater than the
roaming threshold. In various embodiments, the mobile device 110
may begin to scan for a different RF band of the same wireless
network or different wireless network (i.e., a home public land
mobile network (HPLMN) or a visited public land mobile network
(VPLMN)). In the illustrated embodiment, the second RF band 116 in
the second geographic area 120 may be supported by the mobile
device 110. Thus, if the second RF band 116 is available based on
the mobile device's 110 location and has acceptable signal quality,
the mobile device 110 may selectively prioritize scanning for the
second RF band 116 and connect to the second AP 112(N) while in the
second geographic area 120.
Example Computing Device Components
[0026] FIG. 2 is a block diagram showing various components of an
illustrative mobile device that performs optimized scanning for an
RF band. It is noted that the mobile device 200 as described herein
can operate with more or fewer of the components shown herein.
Additionally, the mobile device 200 shown herein or portions
thereof can serve as a representation of one or more of the mobile
device 200 of the present system.
[0027] The mobile device 200 may include a communication interface
202, one or more processors 204, hardware 206, and memory 210. The
communication interface 202 may include wireless and/or wired
communication components that enable the mobile device 200 to
transmit data to and receive data from other networked devices. For
example, the communication interface 202 may include one or more
antennas and a transceiver, among other components. In some
embodiments, the antennas may include an uplink antenna that sends
radio signals. In addition, there may be a downlink antenna that
receives radio signals. In other embodiments, a single antenna may
both send and receive radio signals. The signals may be processed
by the transceiver that is configured to receive and transmit data.
In some embodiments, a receiver and a transmitter may be
implemented.
[0028] In at least one example, the one or more processor(s) 204
may be a central processing unit(s) (CPU), graphics processing
unit(s) (GPU), both a CPU and GPU or any other sort of processing
unit(s). Each of the one or more processor(s) 204 may have numerous
arithmetic logic units (ALUs) that perform arithmetic and logical
operations as well as one or more control units (CUs) that extract
instructions and stored content from processor cache memory, and
then executes these instructions by calling on the ALUs, as
necessary during program execution.
[0029] The one or more processor(s) 204 may also be responsible for
executing all computer applications stored in the memory, which can
be associated with common types of volatile (RAM) and/or
non-volatile (ROM) memory. The hardware 206 may include additional
user interface, data communication, or data storage hardware. For
example, the user interfaces may include a data output device
(e.g., visual display, audio speakers), and one or more data input
devices. The data input devices may include but are not limited to,
combinations of one or more of keypads, keyboards, mouse devices,
touch screens that accept gestures, microphones, voice or speech
recognition devices, and any other suitable devices. Additionally,
the hardware 206 may include one or more sensors such as GPS 208,
which uses space-based satellites that provide positioning signals
that are triangulated by a GPS receiver to determine a geophysical
position of the mobile device 200.
[0030] The memory 210 may be implemented using computer-readable
media, such as computer storage media. Computer-readable media
includes, at least, two types of computer-readable media, namely
computer storage media and communications media. Computer storage
media includes volatile and nonvolatile, removable and
non-removable media implemented in any method or technology for
storage of information such as computer-readable instructions, data
structures, program modules, or other data. Computer storage media
includes, but is not limited to, RAM, ROM, EEPROM, flash memory or
other memory technology, CD-ROM, digital versatile disks (DVD),
high-definition multimedia/data storage disks, or other optical
storage, magnetic cassettes, magnetic tape, magnetic disk storage
or other magnetic storage devices, or any other non-transmission
medium that can be used to store information for access by a
computing device. In contrast, communication media may embody
computer-readable instructions, data structures, program modules,
or other data in a modulated data signal, such as a carrier wave,
or other transmission mechanisms. The memory 210 may also include a
firewall. In some embodiments, the firewall may be implemented as
hardware 206 in the mobile device 200.
[0031] The mobile device 200 further includes a UICC 214 (e.g., SIM
card) that is issued by a mobile phone operator. The UICC 214 can
be various types of UICC (e.g., embedded UICC (eUICC)). The UICC
214 can be used for identifying subscriber services, executing
programs, storing subscriber data, and/or so forth. In the case of
eUICC, the eUICC may receive updates and provisioning information
over-the-air (OTA) from the telecommunications service
provider.
[0032] The processors 204 and the memory 210 of the mobile device
200 may implement an operating system 212, the location services
216, and the RF band connection framework 218. The operating system
212 may include components that enable the mobile device 200 to
receive and transmit data via various interfaces (e.g., user
controls, a communication interface, and/or memory input/output
devices), as well as process data using the processors 204 to
generate output. The operating system 212 may include a
presentation component that presents the output (e.g., display the
data on an electronic display, store the data in memory, transmit
the data to another electronic device, etc.). Additionally, the
operating system 212 may include other components that perform
various additional functions generally associated with an operating
system.
[0033] The location services 216 and the RF band connection
framework 218 may include routines, program instructions, objects,
and/or data structures that perform particular tasks or implement
particular abstract data types. For example, the location services
216 may include one or more instructions, which when executed by
the processors 204, determine the real-time or near real-time
geolocation coordinates of the mobile device 200 based at least on
the location information from the GPS 208.
[0034] The RF band connection framework 218 includes an RF band
scanner 220, a connection module 222, and a look up table 224.
These individual components of the RF band connection framework 218
also include routines, program instructions, objects, and/or data
structures that perform particular tasks or implement particular
abstract data types. For instance, the RF band scanner 220 may
include one or more instructions, which when executed by the
processors 204, scan for service on RF bands supported by the
mobile device. The RF band scanner 220 can scan for RF bands in an
order of preference based at least on the location of the mobile
device 200, the signal quality, and/or the signal strength of the
available RF bands. The RF band scanner 220 may be configured to
perform scanning until the mobile device 200 establishes a
connection to a network. If the mobile device 200 does not
establish the network connection using a more preferred RF band,
the RF band scanner 220 may scan for remaining bands supported by
the mobile device 200 in default order. The RF band scanner 220 can
stop scanning for other RF bands once the mobile device 200
establishes the network connection in order to conserve power.
[0035] The connection module 222 may instruct the transceiver to
connect to the wireless network using an available RF band that has
acceptable signal quality. The connection module 222 may include a
signal quality detector component to detect the signal quality
based at least on transmissions using one or more RF bands that may
include information indicative of Energy to Interference Ratio
(EC/IO), Signal to Interference Plus Noise Ratio (SINR), Reference
Signal Received Quality (RSRQ), Carrier to Interference Plus Noise
Ratio (CINR), and/or so forth. Additionally, the connection module
222 may include a signal strength detector component to detect the
signal strength based at least on transmissions using one or more
RF bands that may include information indicative of Received Signal
Strength Indicator (RSSI), Reference Signal Received Power (RSRP),
and/or so forth.
[0036] The connection module 222 may determine whether the mobile
device 200 is connected to the network. If the mobile device 200 is
not connected to the network, the connection module 222 receives
the geolocation coordinates of the mobile device 200 from the
location services 216. The connection module 222 may also determine
whether the mobile device 200 can connect to the last acquired
network cell. The connection module 222 may also determine whether
the mobile device 200 is roaming. The connection module 222 uses
the geolocation coordinates to identify one or more available bands
that are within the range of the latitude and/or longitude of the
geolocation coordinates from the look up table 224. In various
embodiments, the look up table 224 can include a field for a market
location (e.g., city and state), range of latitude, range of
longitude, available bands, bandwidth for the available bands,
and/or so forth. Upon identifying the one or more available bands
based at least on the geolocation coordinates, the connection
module 222 determines, via the signal quality detector component,
whether the signal quality of at least one of the available bands
is above a predetermined threshold. If at least one of the
available bands has a signal quality above the predetermined
threshold, the connection module 222 identifies that the available
band with an acceptable signal quality is a preferred band. In some
aspects, the connection module 222 may also determine, via the
signal strength detector component, whether at least one of the
available bands has an acceptable signal strength. Thus, if at
least one of the available bands has a signal strength above a
predetermined threshold, the connection module 222 identifies that
the available band with an acceptable signal strength is a
preferred band.
[0037] If there is more than one available band with an acceptable
signal quality above the predetermined threshold, the connection
module 222 identifies an available band with the most bandwidth.
The connection module 222 instructs the RF band scanner 220 to
begin band scanning with the most bandwidth, or the most preferred
band. If the mobile device 200 is unable to connect to the network
using the most preferred band, the connection module 222 instructs
the RF band scanner 220 to search for the band with the second most
bandwidth. Thus, the RF band scanner 220 performs scanning in an
order of preference to speed up the process of selecting a network
cell. If the mobile device 200 is unable to connect to the network
after the RF band scanner 220 performs scanning for all of the
preferred bands, the RF band scanner 220 can resume scanning in
default order.
Example Processes
[0038] FIGS. 3-5 present illustrative processes 300-500 for
optimizing band scanning at a mobile device. The processes 300-500
are illustrated as a collection of blocks in a logical flow chart,
which represents a sequence of operations that can be implemented
in hardware, software, or a combination thereof. In the context of
software, the blocks represent computer-executable instructions
that, when executed by one or more processors, perform the recited
operations. Generally, computer-executable instructions may include
routines, programs, objects, components, data structures, and the
like that perform particular functions or implement particular
abstract data types. The order in which the operations are
described is not intended to be construed as a limitation, and any
number of the described blocks can be combined in any order and/or
in parallel to implement the process. For discussion purposes, the
processes 300-500 are described with reference to the wireless
communication network 100 of FIG. 1.
[0039] FIG. 3 is a flow diagram of an example process 300 for
scanning for an available band in a wireless network when a mobile
device is powered on or when toggled off from an airplane mode, in
accordance with various aspects of the present disclosure. At block
302, the connection module of the RF band connection framework
establishes a connection to a wireless network using a first RF
band. Subsequently, the mobile device may switch off and then back
on or toggle off from an airplane mode. In some aspects, the
location services of the mobile device determine whether the device
has been carried to a new location upon powering on or being
toggled off from an airplane mode. At decision block 304, the
connection module may determine whether the mobile device can
connect to the last acquired network cell using the first RF band
(i.e., the last used band).
[0040] If the device can connect to the last acquired network cell
("yes" response from the decision block 304), the connection module
re-connects to the wireless network using the first RF band, as
indicated in block 302. Conversely, if the connection module is
unable to connect to the last acquired network cell ("no" response
from the decision block 304), the location services of the mobile
device determine the geolocation coordinates (i.e., latitude and
longitude) of the location of the mobile device, as indicated in
block 306. At decision block 308, the connection module determines
whether the latitude and/or longitude of the geolocation
coordinates are within a range of at least one available RF band.
If the geolocation coordinates are not within a range of at least
one available RF band ("no" response from the decision block 308),
the RF band scanner performs a plurality of scans for support by
the wireless network of a second RF band supported by the mobile
device, as indicated in block 318. The scanning is performed in
accordance with a default setting of the mobile device. For
example, bands that are supported by the mobile device may be
scanned in a predetermined order.
[0041] If the latitude and/or longitude of the geolocation
coordinates are within a range of at least one available RF band
("yes" response from the decision block 308), the connection module
identifies at least one available RF band supported by the mobile
device, as indicated in block 310. At decision block 312, the
connection module determines whether the signal quality of the
available RF band is above a predetermined threshold. If the signal
quality of the available band is above the predetermined threshold
("yes" response from the decision block 312), the RF band scanner
selectively prioritizes band scanning starting with the available
RF band having acceptable signal quality, as indicated in block
314. At block 316, the connection module connects to the wireless
network using the available RF band with acceptable signal quality.
If the signal quality of the available band is not above the
predetermined threshold ("no" response from the decision block
312), the RF band scanner performs a plurality of scans for support
by the wireless network of a second RF band supported by the mobile
device, as indicated in block 318.
[0042] FIG. 4 is a flow diagram of an example process 400 for
scanning for an available band in a wireless network when a mobile
device is roaming, in accordance with various aspects of the
present disclosure. At block 402, the mobile device establishes a
connection with a wireless network using a first RF band. At
decision block 404, the mobile device determines whether it is
roaming. In one example, the mobile device may determine that it is
roaming when the signal strength of the first RF band is greater
than the roaming threshold.
[0043] If the mobile device is not roaming ("no" response from the
decision block 404), the connection module re-connects to the
wireless network using the first RF band, as indicated in block
402. Conversely, if the mobile device is roaming ("yes" response
from the decision block 404), the location services of the mobile
device determine the geolocation coordinates (i.e., latitude and
longitude) of the location of the mobile device, as indicated in
block 406. At decision block 408, the connection module determines
whether the latitude and/or longitude of the geolocation
coordinates are within a range of at least one available RF band.
If the geolocation coordinates are not within a range of at least
one available RF band ("no" response from the decision block 408),
the RF band scanner performs a plurality of scans for support by
the wireless network of a second RF band supported by the mobile
device, as indicated in block 418. The scanning is performed in
accordance with a default setting of the mobile device. For
example, bands that are supported by the mobile device may be
scanned in a predetermined order. If the latitude and/or longitude
of the geolocation coordinates are within a range of at least one
available RF band ("yes" response from the decision block 408), the
connection module identifies at least one available RF band
supported by the mobile device, as indicated in block 410. At
decision block 412, the connection module determines whether the
signal quality of the available RF band is above a predetermined
threshold. If the signal quality of the available band is above the
predetermined threshold ("yes" response from the decision block
412), the RF band scanner selectively prioritizes band scanning
starting with the available RF band having acceptable signal
quality, as indicated in block 414. At block 416, the connection
module connects to the wireless network using the available RF band
with acceptable signal quality. If the signal quality of the
available band is not above the predetermined threshold ("no"
response from the decision block 412), the RF band scanner performs
a plurality of scans for support by the wireless network of a
second RF band supported by the mobile device, as indicated in
block 418.
[0044] FIG. 5 is a flow diagram of an example process 500 for
selecting a preferred band to scan from a plurality of available
bands. At block 502, the location services of the mobile device
determine the geolocation coordinates (i.e., latitude and
longitude) of the location of the mobile device. At decision block
504, the connection module of the RF band connection framework
determines whether the latitude and/or longitude of the geolocation
coordinates are within a range of at least one available RF band.
If the geolocation coordinates are not within a range of at least
one available RF band ("no" response from the decision block 504),
the RF band scanner of the RF band connection framework performs a
plurality of scans for support by the wireless network of a second
RF band supported by the mobile device, as indicated in block 516.
The scanning is performed in accordance with a default setting. For
example, bands that are supported by the mobile device may be
scanned in a predetermined order.
[0045] If the latitude and/or longitude of the geolocation
coordinates are within a range of at least one available RF band
("yes" response from the decision block 504), the connection module
identifies at least one available RF band supported by the mobile
device, as indicated in block 506. At decision block 508, the
connection module determines whether the signal quality of the at
least one available RF band is above a predetermined threshold. If
the signal quality of the at least one available RF band is not
above the predetermined threshold ("no" response from the decision
block 508), the RF band scanner of the RF band connection framework
performs a plurality of scans for support by the wireless network
of a second RF band supported by the mobile device, as indicated in
block 516.
[0046] If the signal quality of the at least one available RF band
is above the predetermined threshold ("yes" response from the
decision block 508), the connection module determines whether there
is more than one available RF band with acceptable signal quality,
as indicated in decision block 510. If there is only one available
RF band with an acceptable signal quality ("no" response from the
decision block 510), the RF band scanner selectively prioritizes
band scanning starting with the available RF band having acceptable
signal quality, as indicated in block 514. If there is more than
one available RF band with an acceptable signal quality ("yes"
response from the decision block 510), the connection module
selects an RF band with the most aggregate bandwidth, as indicated
in block 512. For example, the connection module may select the 5
GHz band if the 5 GHz band and the 2.4 GHz band are both available
and have acceptable signal quality because the 5 GHz band may
provide higher bandwidth and support for more transmission modes
than the 2.4 GHz. If the mobile device fails to make a connection
after performing scans for support by the wireless network of the 5
GHz band, the RF band scanner may scan for an available band with
the second highest bandwidth having an acceptable signal quality
(e.g., 2.4 GHz) and so on until the mobile device connects to the
network.
CONCLUSION
[0047] Although the subject matter has been described in language
specific to structural features and/or methodological acts, it is
to be understood that the subject matter defined in the appended
claims is not necessarily limited to the specific features or acts
described. Rather, the specific features and acts are disclosed as
exemplary forms of implementing the claims.
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